Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar data disclosure. A public calendar block can be used as a pivot point to access private calendar data. The Concrete CMS security team thanks Winston Crooker for reporting this issue.
Update concrete5/concrete5 to 9.5.1 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanConcrete CMS is vulnerable to authorization bypass in the Calendar Event Frontend Dialog affects concrete5/concrete5 (composer). Severity is medium. Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar data disclosure. A public calendar block can be used as a pivot point to access private calendar data. The Concrete CMS security team thanks Winston Crooker for reporting this issue.
AI coding agents often install or upgrade packages automatically in composer. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| concrete5/concrete5composer | <9.5.1 | 9.5.1 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar data disclosure. A public calendar block can be used as a pivot point to access private calendar data. The Concrete CMS security team thanks Winston Crooker for reporting this issue.
Update concrete5/concrete5 to 9.5.1 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanConcrete CMS is vulnerable to authorization bypass in the Calendar Event Frontend Dialog affects concrete5/concrete5 (composer). Severity is medium. Concrete CMS 9.5.0 and below is vulnerable to authorization Bypass in the Calendar Event Frontend Dialog which can allow cross-calendar data disclosure. A public calendar block can be used as a pivot point to access private calendar data. The Concrete CMS security team thanks Winston Crooker for reporting this issue.
AI coding agents often install or upgrade packages automatically in composer. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| concrete5/concrete5composer | <9.5.1 | 9.5.1 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardReported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard